Monsanto's methods are spelled out in a series of confidential commercial licensing agreements obtained by the AP. The contracts, as long as 30 pages, include basic terms for the selling of engineered crops resistant to Monsanto's Roundup herbicide, along with shorter supplementary agreements that address new Monsanto traits or other contract amendments…

For example, one contract provision bans independent companies from breeding plants that contain both Monsanto's genes and the genes of any of its competitors, unless Monsanto gives prior written permission — giving Monsanto the ability to effectively lock out competitors from inserting their patented traits into the vast share of U.S. crops that already contain Monsanto's genes…

"We now believe that Monsanto has control over as much as 90 percent of (seed genetics). This level of control is almost unbelievable," said Neil Harl, agricultural economist at Iowa State University who has studied the seed industry for decades. "The upshot of that is that it's tightening Monsanto's control, and makes it possible for them to increase their prices long term. And we've seen this happening the last five years, and the end is not in sight."